1. Field of the Invention
The invention relates to a housing structure for mounting optical elements, in particular of a projection lens housing in a projection exposure system for manufacturing semiconductor elements, attachment locations, which have connecting parts, for connection to a supporting structure being provided on structural elements.
2. Description of the Related Art
A housing structure of the kind mentioned in the introduction is described in EP 1 278 089 A2. The housing structure constitutes, in a projection exposure system, the housing of a projection lens, in which a plurality of optical elements, such as, for example, lens elements and mirrors, are mounted. The housing structure or projection lens housing is provided with attachment locations on structural elements, at which, via connecting elements, the housing structure is supported with its weight on a supporting structure of the projection exposure system since the housing structure is suspended into the system. In this connection, the attachment locations are also to be provided in such a way that kinematically defined mounting is brought about, exchangeability also having to be ensured.
For various reasons, the housing structure is, in particular in projection exposure systems in the EUV range, made from a glass ceramic structure, On the other hand, the supporting structure of the projection exposure system is made from a different material, in general from a metal material. This means that the connection between the housing structure and the supporting structure is problematic owing to the different materials, in particular with regard to stability, thermal expansion coefficient and temperature differences.
For further prior art, reference is made to US 2003/0162484 A1 and EP 1 338 911 A2.